Coronadite

Formula:  Pb(Mn,Mn)₈O₁₆

Origin of name:  For F. de Coronado, Spanish explorer

Crystal system:  Tetragonal

Crystal class:  2/m

Twinning:

Unit cell:

Colour:  Dark grey to black

Diaphaneity:  Opaque

Luster:  Submetallic to dull

Habit:  Massive; botryoidal crusts with fibrous structure

Hardness:  4.5 to 5

Specific gravity:  5.44

Cleavage:  None

Tenacity:

Streak:  Brownish black

Synonyms/varieties:

Comments: